i was wondering is there any .Net Built in libraries that can help me with my objective ?
Short answer: No, at least not at the present time.
The .NET framework does not provide any direct support for recording audio. This is the reason libraries like nAudio exist. You would neeed to use Com Interop and the Windows API to acheive this, and it would be no small task. Even the Coding4Fun article on recording sounds at Microsoft's Channel 19 website uses NAudio. Your best bet would be to follow their example.